An advert depicting people in Britain who have been forced into prostitution, domestic servitude and agricultural slave labour aired on Wednesday as part of a two-month national campaign by the Home Office that aims to encourage modern-day slaves to seek help from the government, and the British public to report persons suspected of enslaving others.

The focus of the 30-second commercial and the campaign's tagline – "Slavery is closer than you think" – is designed to raise awareness that "these examples of slavery are taking place in a recognisably British setting", the Home Office said.

Slavery remains a problem in the UK, with 1,746 reports of potential trafficking victims last year, according to the national referral mechanism. Albania, Nigeria, Vietnam and Romania were the most common countries of origin.

"Victims are exploited for sex, labour (agriculture, maritime, labouring), domestic servitude and criminal activities. The most prevalent exploitation type for both adults and children is labour exploitation," the Home Office said.

A national helpline, supported by the National Society for the Prevention of Cruelty to Children (NSPCC), is being launched to offer information and advice to child and adult victims of slavery, as well as to professionals and members of the public. A website will enable whistleblowers and slave labourers to seek help.

"It is difficult to accept that modern Britain is home to slavery, but this appalling crime is taking place here – often out of sight – in shops, fields, building sites and behind the curtains of houses on ordinary streets," said the home secretary, Theresa May. "The first step to stamping out modern slavery is acknowledging and confronting its existence. This campaign aims to bring this hidden crime out into the open and challenges us all to report it wherever we suspect it."

The campaign comes as the issue of modern-day slavery is gaining political traction. The UK published the modern slavery bill on 10 June, which includes provisions such as the creation of an anti-slavery commissioner and harsher penalties for traffickers. A parliamentary joint select committee criticised the bill, which is now being scrutinised by parliament, for failing to do enough to protect victims.

Aidan McQuade, director of Anti-Slavery International, said: "It is good that the government is trying to raise awareness of modern slavery, but it would be even better if it improved the modern slavery bill. Including thorough victim protection, reintroducing migrant domestic workers' right to change employer, tackling transparency in supply chains and making the anti-slavery commissioner role truly independent would be a good start."

"It's horrifying that 180 years after slavery was officially abolished, children and adults in the UK are still victims today," the NSPCC's director of national services, Peter Watt, said. "Please trust your instincts and call the helpline if you are concerned that someone may be at risk."

When trafficked women finally break free of their abusers, they turn in desperation to the authorities. This is only the start of a new nightmare. Four women tell Amelia Gentleman about their slavery, escape and further detention by officials they thought would help them